The invention relates to a removable modular control device for a contactor apparatus comprising power switches which are actuated by an electromagnet having an energization coil which comprises a first end permanently connected to a pole of a power supply source and a source end connected to a selector circuit capable of transmitting control signals of opposite polarity to that of the source. These control signals are provided either by an automatic device, or transmitted by a means independent of the preceding one.
Control systems known in the prior art generally require a cabinet or a board in which is usually disposed a function selector which able to orient either the signals emitted by the circuit of an automatism or the signals which must be applied independently of the preceding ones towards one of the ends of the coil, for checking for example the correct operation of a particular contactor by a manual forced operation and interruption order.
In one embodiment which is widely used, the selector is disposed not on the panel of a cabinet but on the front face of the cover of a small box containing the contactor with which it is connected by conductors going from the cover to terminals connected to the coil of the contactor, the latter being fixed on a face of this box.
In both cases, the member for controlling the selector, which is disposed accessibly, may be incorrectly manipulated or inadvertently moved, whereas its presence is only justified by the infrequent need to carry out an operating check.
Furthermore, it can be seen that in each of these cases it is necessary to use more or less long conductors which are themselves likely to be the cause of breakdowns or troubles.